Radio tuning device



B. A. SCHWARZ ET AL RADIO TUNING DEVICE Jan. l0, 1950 2,494,008

2 Sheets-Sheet l Filed March 3l, 1948 Jan. l0, 1950 B. A. SCHWARZ ET AL2,494,008

' RADIO TUNING DEVICE Filed March 31, 1948 2 sheets-sheet 2 PatentedJan. 10, 1950 RADIO TUNING DEVICE Bertram A. Schwarz, Howard M. Stelzl,and Manfred G. Wright, Kokomo, Ind., assignors to- General MotorsCorporation, Detroit, Mich., a

corporation of Delaware Application March 31, 1948, Serial N0. 18,154

(Cl. 'i4-10.33)

6 Claims.

This invention relates to position indexing means and more particularlyto radio tuning means, commonly referred to as push button tuners, andmore specically to the power transfer means between the manual tuningdevice and the tuning means per se. Inasmuch as the connection betweenthe manual tuning knob of a radio receiver and the movable tuning meanstherefor must of necessity be of relatively large gear ratio andmaintain its adjusted position, it has been common practice to use forthis drive a worm wheel and gear. This type of connection provides arelatively large mechanical reduction, and at the same time anirreversible mechanical drive, so that while-the manual knob may turnthe worm Wheel and thus the gear, it is impossible for the gear to driveback through the worm Wheel and thus it locks the tuning mechanism inits adjusted position. This is particularly necessary, of course, inautomobile sets, where there is considerable vibration of the parts.When push button tuners or automatic tuning is used in conjunction witha manual drive, itis, of course, necessary to disconnect the manual wormwheel drive at such times as the push button is actuated, so that thetuning means per se is unlocked and may be moved to its new position.Also, during resetting periods of one of the push buttons, it isnecessary to have the disconnect means or clutch in engagement to holdthe device in `its newly set position until the mechanism has beenlocked.

It is therefore an object of our invention to provide suitabledisconnect means in a tuning device between the tuning-means and themanual tuner.

It is a further object of our invention to provide clutch means betweenthe tuning means and the manual tuner which is automatically operated byoperation by any one of the mechanical push buttons.

It is a still further object of our invention to provide clutch means ina radio tuner which releases during normal operation of the push but tontuner but remains in yengagement in the resetting operation to maintainthe tuner in proper position prior to lock-up of the cams.

With these and other objects in view which will become apparent as thespecification proceeds, our invention Will be best understood byreference to the following specification and claims and theillustrations in the accompanying drawings, in which:

Figure 1 isa top plan view with parts broken away of a tuner for a radioreceiver embodying our invention.

Figure 2 is a sectional view through the clutch drive of our invention.

Figure 3 is a sectional view taken on line 3-3 of Figure 1 with partsbroken away.

Figure 4 is a top View of the tuner `embodying our invention similar toFigure 1, but showing a. diiferent position of `the operating members.

Figure 5 is a view taken on line 5 5 of Figure 4;

and- Y Figure 6 is a sectional view taken on line 6--8 of Figure 4.

In referring to so-called push button tuners, there have been on themarket many mechanical types of such indexing means for adjusting radioreceivers. Pressure `exerted on a button projectlng from the set eitheraxially along the shaft supporting the same or pivotally around a pivotto cause an adjusted part to move the tuning means are commonconstructions used. However, many of these wererather difficult to resetto a new position or readjust to an old one after repeated usage hadcaused drift. The manually engaged button generally had to be removedand a screw or bolt which thereby became accessible loosened to releasean adjustable cam on the reciprocating shaft. Then the station wasmanually tuned in and the shaft and screw assembly forced inwardly untilthe adjustable cam came in contact with the turnable means connected tothe tuner, and while in this inward pressed position, the screw or bolthad to be tightened. This locked the cam in its adjusted position. Thisoperation not only required the use of both hands of the operator, butalso the forcing in of the screw and the tightening of the samesimultaneously.

In order to alleviatethis situation and to provide a simpler set-upmechanism, we devised a. novel tuner which could be unlocked or have oneof the adjustable cams freed by pulling outwardly on the associated pushbutton and its shaft, the button in this case being rigidly secured tothe shaft, to cause the same to move further out than when in ordinaryinactive position. This caused two parts of the shaft-assembly to moverelatively and unlock the cam carried thereby. This, of course, could bedone simply with one hand and is fully shown and described in our PatentNo. 2,489,544, issued November 29, 1949, titled Radio tuning means,which patent is directed toward the lock-up means for the cam. After thecam is unlocked, as previously described, the receiver is manually tunedto the station that it is desired'to set up for that particular pushbutton. The -push button is then forced inwardly, and as it moves thecam first contacts the movable means, which may be in the nature of atreadle bar construction which is secured to the 5 member I8 and permitsthe same to rotate outtuning means, and this turns the cam to its properWardly to unlock the cam. In order to now reset index.During-th's'tiir`ie"it is desiredto Amainthe receiver lis-firstmanually; tunedl and;- upon tain the irreversible- Worinldrivefinfcontact and pushing inwardly .ion thtbuttori following' thislock the tunng means in position, and it can also unlocking, the cam isbrought into indexing posibe used to make any final smalladjustmentilditir first, or that in which it engages the treadlenecessary. i bar tobe described, and then any further move- However, assoon as the cam has beeni'nd'e'xed', ment causesthe strap 20 to moveuprthe incline any further inward motion oflatl'iepush'button--,32an'd-re1'oc'k the-samerA will cause locking of the carni-byxYeansrspeciii-f- The tunin'gmeans'for the receiver in this case callyset forth in the above-identid applicationfl215`ychas?been-sliwn'las@the comminuted core or perand to be furtherdescribed herein. At this point meablity'l' tunedlfftyp-l although itcould just as the manual drive should be disconnected from,`V1 Wellbeanyeother, and consists of several coil the tuning means, or released,and our construe#` units 34, `whichare` used in conjunction with a tionprovides this feature. Also, in norm'alfopere l pluralityoflfcomminutedcore units 36, which are ation of push button tuners, it is desirable to20 supported on atransverse-bar 38, and adapted to maintainthe manualdriveconnectedfto the-.tunfbe'zmovedcirnorifout ofthe-:coilsras-ftherstatiorr ing means, When the set is on stationandlthetun` l position-dictates.- This transverselmember,which@ -Yingsbu-ttonsf anesinactive' -faseths 1ocks=.itin that isfmovableilongitudinally fine-slide '--slot-sfA-4I) khasn. position. Whenthe operatonfforces-one-of theystraight lmet-motioniandfismovedback-andforth,n buTttons-fgin,fthewrnanual-fmeansashould `rbe sub'-= 25.by link=membersAron-*eachendfiwhichextends stantiallyimmediatelyreleased prior .to the time from-thauppenend'.ofoppositelyadisposed larms that the camifcomesfinto engagement:withv` the IIII,` which f are-:pivotedfon'toneaendraround pi-vgp,treadle'lbaf softhatetheI-fsame; willbe as' free as-"- 46: adjustably-.he1dfinposition by-.nuti hand Von possibleand'fon'lya smallamount-'of'force will be l the oDIJositeend-in v`bearingilfi1-,.-said-4arms-having@ nec'essary'torturr the tun-ingimeans to -thisnewoextended@between{themtinsparauel relationw0a position. Immediately uponrelease of the pushitransversel rods .5o.-andwywhiehare disposed...-blftten the" @hitchfnaHSf/ShoudfagaD-fengage t0 equal` distances onoppostesides-of thef-faxisand lock the same in its new position. Inotherlwords', which Lat, 9,5.:9, .treadie-bap-.fghthe @amsn3,;..tha1.,..= the',fmariuailetun'ng-aneansihas:a secondffunctiony' is#vthe. push. button.assemblyyprojecbs,..throughgs n'crrle'lyail'raif'.lGMOGKHSHI@ tuning meansfin poe-35 ,between -Athese;`transverswrodsgthef-aXisf-OfA :theY Sit'n dmi'giieptn 'from 'afpfltillar 'stai/i011, earnsl bei-ngvsubstantiallycthat Jofthetreadle--1;bar-- and drlringsuchltimes-as the/automatic push butwhen-in- Vrfullengagenrentnso.thatV ,as"thecam^ f, torislarent actuatedwpointsengage onerodi or-the othergfthey turn-thee.'

Referrririgfmow more fspecieallyato fthe fdraw i i Sametodiferent.angu1ar:pogitions, e iugm-the tunen'whi'chisused.ftoiltustrateou1-=inf4nu (Jn-One end.-0f,the; asgemblygor..the-treadlefbar..f,

ventionfcomprises a main-frame 2 upon-Which are f slidably'mountedf aipluralityaofareoiprocating `assembliesindicatedsgenerallwat t: These:assemf` bliesiareridential and1=iricthe mainfare madefup a.of-twoparal-'lel bars- 6 kand e'lhfwlfrich l-are 'adaptedff-45totbes@.securedtogethertliatftheyzmay =haverelative'ilongitudfinafmovments Bars-B extender?" substantiallythe-ful-l length-oftheffassembly- .and-Svis'trurrnionedsirrariaoperiirrgal 0 in oneofthezfrontltransversesfrafn'emember aridin anpeni'ng-r-I 2; i450inathea'ear. transverse fra'xne-memberf I4; On this f bar 8 *there`ispivotally .mounted-fa nam. I wwhich is dae" adjustableffmembmfThs'fcamfv is spring.l locked againstfthebarbyza -rrrembertv I 8,vWhiehis-f piybtallyfpulled irrtov/aridfthenbarr 8 byl Aa strap i207; 55extending1 eoverlaiprojecting'rend-'l 21o-f f the lmen'if ber: I 8 toVbiasf'itittwvaifd ithefbari- 8 iricertainposi`-,v tions. A helicalspring 24 is mounted around tliewl proj eating@ inner- Sv'endEfroftheeiba-re 8 2 and: presses againstfthe inner surfaepf.thevtransversefy inem- 60. berf' I 4 'and againstf a 'shoulder ontheifbar f8 Y` to` causeftheasame v"toebe''spring -oiasedato 'its Iouter-Lmost;po"si-tieml,A Y

Thefsecondbari 'extenidsiodtfbeyond the bar` '8 inrfrontfoftherrtunerzandlcarries-ra manually en; fc5 gageable push buttonr-ZrfThe'finner-end of the-fbar- -ise'turnedat right'anglestoffprovide -anengra-ging footi'28for clutchoperation'. Thefmeans 1' forflockingauptheYcarni 6 vasnabovementionedis ithe-fsubjectrmatterprouvent-pending:applicationff7o and will not;`befdiscussedeherefin =detailfexcept to s' say- .-tliatfto` ,'unlock icamel-I 6 the :operator pullsi uponpushfibutton- 26,wvhichfcausesbar-6to move outwardly ,Yvvitlp respect tofbar 8 sincel Athat vcanonly move`1out,apredeternrinedarrrount, due` toas 75 stop 30 which engages thefront transverse member. Upon the bar 6, therefore, moving out- Wardlywith respect to the bar 8, the cross-strap 26 slides down the inclinesurface 32 on the spring i 'I' inthe side-.plata of the frame, andprojects out to some fdistanceffrom said-isidemembershavingsyrigidlysecured to-theffprojectinguendfbysset screw 'f fV 456 orother,suitablemsecuringtmeans 2a clutchfdiscelV whichlhas-va bearingsupportwinfafbracket'62 s cured to thesiderplaten Thisfsleeveihasrigidly, j

rotatably'fsecuredrta second .gear 66 iofuthesamey L diameter, which is:.spr-ing:V @loaded byf-spring p6B-*rf for-:anti-backlashA-vhelicaflsspringwl 0- surrounds thefsleevev 602 andzetendsetovforceiti toward aneV i outermostl positionn .asf-shn vn;rv inf-*Figure 12...Ar.v Worm gear 'I2 rotatably supported in bracket 514,1,

alsoheld .by-z-bracketaZ, engagesthesteeth ofY the I)from themanualfknobT18.- Theoutei: endoffthe.

sleeve 68 carries a clutchplate i'ftvhiclnfis:adapt treadleibarlff.

The operator for the clutch is'm'eans whichiwillxi smove'the:rotatablessleeve .66 :'tofonevsidel aga-instiV c yonlyirotaterthesleeves 1 60W-and@ ino @mation willi 1:te.Qtrarisniitted:ta-:thee .i

the force of the spring 70, and this is accomplished by a lever 84whichhas one end pivoted in a slot 86 in an angle member on the frame, andwhich then proceeds to encircle a circulargroove 88 in the sleeve 60 toform a collar, the outer end of which member is turned to form two'parallel sides 90 which supports a small roller.92 therein. This memberhas a small spring 94 ltending to spring bias this end toward the frame,but this spring is much weaker than spring 'l0 in compression. To causethis arm to pivot and to move one of the clutch plates, there isprovided a transverse rotating member 96, which lies below and to therear of the reciprocating assemblies and is pivot-` ally mounted inopposite sides of the frame and has a series of spaced fingers 98 whichproject toward the feet 28 of the reciprocating assemblies and which areadapted to be engaged by the same in certain positions, and also anlangled endl which extends out around the roller 92 and the angled end|02 of which is adapted to engage the roller as the assembly rotatesupon pressure exerted on any one of the iingers 98. This assembly isspring biased in a clockwise direction as shown in Figure 5 or Figure 6by a coil spring |06, wound around a portion of the member and havingits end snapped over stop |06 on the frame. Figure 5 illustrates thecontour of the operating end |02 where it is best shown, the dotted lineposition being the one in which it does not engage the roller 92 and theclutch is in contact, land the full line position being that in which itengages the roller 92 and forces the arm 84 to move the sleeve 60against the force of the spring 'l0 to disengage the clutch plates.Figure 6 best illustrates the turning operation of the member 96 whenone of the feet 28 of one of the reciprocating assemblies engages itsassociated curved finger 98 oi the number 96 to cause the member to turnupon reciprocation of the assembly.

To best understand the operation of the device, reverting to a previousstatement for the moment, it is desirable to normally have the tuningconstruction, namely the transverse bar 38 and the associated treadlebars, normally locked in an adjusted position, and this is accomplishedby having the manual knob secured thereto through the friction clutchunder ordinary circumstances. The worm drive is irreversible and afterthe knob 18 has been turned to bring in a desired station, the mechanismwill remain substantially in place. If, however, it is desired to movethe tuning means to a new position by one of the push buttons, then therst thing that is desired is to disconnect the manual drive so that thetreadle bar and transverse bar only may be easily moved by the cam.Therefore, the initial movement of the reciprocating yassembly causesthe foot 28 of the same to force against the finger 98 and cause member9B to rotate, bringing arm |02 up over wheel 92 to disconnect theclutch. Thereafter, any further movement of the reciprocating assemblywill bring its cam I6 into engagement with the treadle bar transverserods 50 and 52 to index the same. Upon return of the push button to itsinitial position, the clutch will again engage and lock the same in itsnew position.

Assuming for the moment that it is desired to reset the cam I6 to -a newstation instead of merely to index the mechanism to the station alreadyset, the associated push button 26 is pulled outwardly, which causesrelative motion between bars E and 8 and unlocks cam IB. The two barsare then in their extended positions. The clutch 80-58 is in engagementand the operator can now set the receiver to receive the desired stationto be set up."-

The operator then begins to force the assemblyi that occurs is that camI6 engages the treadle bar transverse rods 50 and 52 to reset the `camto its new position. Up to this time it is desired to keepthe mechanismlocked and the clutch in contact.v After the cam is indexed, it is thennecessary to lock the same and this is caused by further inwardmovementby the push button, which only carries with it now bar 6, as bar 8 hasstopped. This relative motion causes strap 20 to ride up on the surface'32 of the member I8, which locks the cam and at the same time foot 28presses against iinger 98 to disengage the clutch and permit the tuningmeans to turn. Thereafter, the button isreleased and repeated operationsfollow the'samepattern as previously described.

Itis thus evident that our construction provides for locking themechanism in position as desired" and automatically releases the same atsuch times as is necessary for automatic operation.

We'claim:

1. In means for tuning a radio receiver, an adjustably positionablemember secured to the tun-r ing means for the receiver, manual drivemeans for moving said member, clutch means interposedj between themanual drive and the member so that the latter may be disconnected, aplurality of as# semblies mounted for reciprocating movement toward themember each assembly including 'a1 plurality of slides having limitedrelative longi-A tudinal movement, adjustable cam means on one of theslides of each assembly to selectively con-` tact the positionablemember upon movement toward the same, locking means for the cams on saidslides actuated by relative movement of the same and clutch operatingmeans engageable by one slide of any of the reciprocating assemblies asit is forced inwardly to operate the clutch and disconnect the manualdrive so that small rotative forces may turn the member.

2. In means for tuning a radio receiver, an adjustably positionablemember connected to said tuning means, manually engageable rotatablemeans, a plurality of reciprocating assemblies mounted toward the membereach assembly including a plurality of slides having limited relativelongitudinal movement,'adjustab1e cams on each reciprocating assembly toengage the member to move the same, irreversible drive means between themember and the rotatable means, clutch means interposed in the drivemeans between the irreversible means and the positionable member andclutch operating means actuated by movement of any one of thereciprocating assemblies when said slides are at one limit of theirrelative motion but incapable of clutch actuation when at the otherlimit of movement as the assembly moves inwardly to cause clutchseparation and disconnect the irreversible drive.

3. In means for tuning a radio receiver, a rotatable member connected tothe tuning means to move the same, manually rotatable means, a worm gearconnected to said means, a worm wheel engaging said gear, clutch meansconnected to said wheel and to said rotatable member to transfer motionfrom one to the other, mounting means for said worm wheel so that it mayboth rotate and move axially to a limited degree, said axial movementcausing clutch actuation.

4. In means for tuning a radio receiver, a rotatannabee' each includingan adjustable cam mounted tor move in a plane normal to the rotatablemember to force the cam carried thereby against the same, saidassemblies including two bars capable of relative'longitudinal movementbut normally locked for simultaneous movement, a proe jection on one ofsaid bars, and clutch operating means mounted to be engaged by any ofsaid projections if said bars are locked as the assembly is movedinwardly to actuate the clutch and disengage the manual drive so thatthe cam may index the tuning means.

5. In means for tuning a radio receiver, an adjustable positionablemember secured -to the tuning means for the receiver, a plurality Aofassemblies mounted for reciprocating movement toward the member andaxially spaced along the same, said assemblies including two partshaving a limited amount of relative longitudinal motion, a camadjustably mounted on one part of each assembly to engage the memberupon movement toward the same, locking means for the cams on the partsactuated by relative movement between the two parts, manual drivemeans,.- clutch means between the manual drive meansv and the member,clutch operating means and a projection from each of the assembly partsnot carrying the cam Vfor .engaging the clutch operating means when .theassembly is moved toward the member, the de-clutching action beingvaried by the relative position of the twoY parts of the assemblies. l

adjustable positionable member secured to the tuning meansr for thereceiver, manually `rotatable means including an irreversible drive,clutch means interconnecting .said manually rotatable means Awith saidpositionable member, a vpluralityl of vtuning .assemblies .mounted forreciproeating movement toward the member and axially spaced .along itslength, each assembly including -a plurality of l'parts having a limitedamount of relativev longitudinal movement, adjustable cam .means mountedlon lone of the parts of each assemblyfmeans on each assembly forlocking the :cam againstY movement and actuated by A relative movementof said parts to one extremity of said movement to lock the `cam and tothe otherV extremity to unlock rthe same, means for dis-- engaging saidclutch and means for actuating the d-isengag-ing ymeans for the clutchon one of the parts -on each assembly, so located that if the parts arelocked together to lock the adjustable cam in place, the clutch-disengaging means will be operated, but if the cam is unlocked and theassembly parts are at' the other extreme of their relative motion, theclutch vactuating means will not be moved.

BERTRAM A. SCHWARZ.

HOWARD M. STELZL.

MANFRED G. WRIGHT.

.REFERENCES CITED The following references .are of record in the lil-eof this patent:

UNITED sTATEs PATENTS Certificate of Correction Patent No. 2,494,008January 10, 1950 BERTRAM A. SCHWARZ ET AL.

It is hereby certied that error appears in the printed specification ofthe above numbered patent requiring correction as follows:

Column 6, line 49, after the Word mounted insert to move;

and that the said Letters Patent'should be read with this correctiontherein that the same may conform to the record of the case in thePatent Oiiice.

Signed and sealed this 16th day of May, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

